popoeliz

1st category: fighting dog group. e.g. American pit bull. They typically breed in aggressiveness. Or they suddenly attack owner or passer by. They may be most friendly family pet but there is a risk that you don't want to take with your own children.
2nd category: difficult to train dog or stubborn dog. e.g. standard schnauzer (they are great dog, if it is your second dog)
3rd category. dog from a pet shop or puppy farm. This applies to any dog. This group of dog did not have socialization with the litter (puppy need to stay with the bitch/mother for ~12weeks to learn and socialize). Do you want to risk to have a dog that is mentally damaged by locking up in the pet shop in its childhood? Try to get a dog from a breeder, can be professional or amateur. Try to look at the dad and mum, to see whether you like them(personality, traits)

Then the factor is how much space do you have? How much time do you have to exercise the dog. Do you have young children? Do you have time to groom the dog? (if you want a dog with long hair)

I live in a house overseas. The first beginner dog/easy to care for dog comes in mind are:
Golden retriever or Labrador.  First small beginner dog that comes in mind is king charles spaniel or Maltese.

To be fair to standard schnauzer, they are the smallest dog with big dog personality. But you need to train and discipline them properly. I am keeping one currently, low shed, low odour...
They are great dog but I would not be able to handle her if I have not had dog before.

Remember, the extra cost of buying a dog from a reputable breeder is your least of your worry.
e.g. buying a pure breed standard schnauzer (not for breeding) is ~800. Cost of keeping a dog including vet, food per year is at least 1500. (vet bill, vaccination, heart worm tablet~$600 or more in a year that the dog does not have any discease)